<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>iframe</title>
    <script>
        function go() {
            var url = document.getElementById("url").value;
            document.getElementById("iframe1").src=url;
        }
    </script>
</head>
<body>
    <div>
        <p>请输入地址：</p>
        <p>
            <input type="text" id="url" value="https://www.bilibili.com/">
            <input type="button" value="提交" onclick="go()">
        </p>
    </div>
    <div>
        <iframe id="iframe1" style="width: 100%; height: 500px;"></iframe>
    </div>
</body>
</html>